Thread: Is insect protein preferable to fish meal in Koi food?

Is insect protein preferable to fish meal (protein) in 'high quality' Koi food? As far as I understand it, is that fish meal is in Koi food as an easily digestible protein. Is that really preferable over insect protein? It is what they would naturally eat after all.

Lots of insect protein feeds cropping up in recent years. Probably because reptile keeping and breeding insects to feed them is massive business now. The koi feeds seems a natural progression.

And crucially the insects, as a protein source, has no Japanese monopoly on it.
Anyone know why everyone recommends fish meals over insects?

I've always hand fed calci worms as they love them. I do that 70/30 with a big pot of all sorts (mainly Cuttlebrook growth).
I auto feed sinking only. I love the aller aqua primo. If there was an insect protein sinking colour feed I could mix in. I'd be all over it...
...might try one of the insect feeds when the pot of floating allsorts runs out.

The suitability of insect meal as a replacement for fish meal depends on the species of fish that are made into fish meal and the species of insect in insect meal and, of course, the quantity of the meals in different foods; neither of which are revealed by the manufacturer.

I had continuous headaches while I was researching and writing the Advanced Koi Nutrition course I teach for Koi Organisation International especially where amino acid requirements were concerned since some amino acids are essential so they must be in the diet because they can't be synthesised while other amino acids can be synthesised if the precursors (stuff to make them) are already in it.

My assessment of the two types is that insect meal based food made with a high proportion of Black Soldier Fly does have a suitable amino acid profile compared with a fish meal food that has an high proportion of fish meal. Therefore a good quality food, whether fish meal or insect meal based, will have the correct make up of ingredients and cheaper foods will have good advertising literature but less of the more expensive ingredients.

So, if anyone wants to try an insect based brand, it would be sensible to try it for a while and compare the growth, body and colour development and the waste of the new food with the original food.

Sorry, apart from saying that a good insect food could be just as suitable as a fish meal food, I haven't made a ground breaking statement because that is obviously what we do already

If anyone would like to compare the analyses of a typical Black Soldier Fly Meal (BSFM) with a typical Fish Meal (FM) to see if they can make a better assessment, here you go a free of charge headache courtesy of Manky

Thanks Sid.
So it's fair to summarise, I suppose, Dunno, Maybe, it's possible?

Originally Posted by Manky Sanke

The suitability of insect meal as a replacement for fish meal depends on the species of fish that are made into fish meal and the species of insect in insect meal and, of course, the quantity of the meals in different foods; neither of which are revealed by the manufacturer.

I had continuous headaches while I was researching and writing the Advanced Koi Nutrition course I teach for Koi Organisation International especially where amino acid requirements were concerned since some amino acids are essential so they must be in the diet because they can't be synthesised while other amino acids can be synthesised if the precursors (stuff to make them) are already in it.

My assessment of the two types is that insect meal based food made with a high proportion of Black Soldier Fly does have a suitable amino acid profile compared with a fish meal food that has an high proportion of fish meal. Therefore a good quality food, whether fish meal or insect meal based, will have the correct make up of ingredients and cheaper foods will have good advertising literature but less of the more expensive ingredients.

So, if anyone wants to try an insect based brand, it would be sensible to try it for a while and compare the growth, body and colour development and the waste of the new food with the original food.

Sorry, apart from saying that a good insect food could be just as suitable as a fish meal food, I haven't made a ground breaking statement because that is obviously what we do already

If anyone would like to compare the analyses of a typical Black Soldier Fly Meal (BSFM) with a typical Fish Meal (FM) to see if they can make a better assessment, here you go a free of charge headache courtesy of Manky

Brilliant Post Syd, thanks for sharing.

I notice Cysteine is rather lacking in the BSF, yet I thought this amino acid was an essential factor for good growth, general health, stress reduction and immune system as well. Also noted is the slightly lower amount of Methionine.

Being unsure about this I posed some questions to AI:

Would a reduced amount of Cysteine in the diet affect the growth and health of Koi Carp?

Yes, a diet lacking in cysteine will negatively impact the growth and health of koi carp. As a semi-essential amino acid, cysteine plays a critical role in several biological processes, and a deficiency can lead to poor growth, a weakened immune system, and increased vulnerability to stress and disease.

Reduced growth and poor body condition


Cysteine is one of the key sulfur-containing amino acids, along with methionine. Since fish can synthesize some cysteine from methionine, the total requirement for both is often considered together. If the overall total sulfur amino acid (TSAA) level is insufficient due to a lack of cysteine, the fish's ability to build and repair tissues is compromised.

• Poor utilization of protein: A lack of balanced amino acids can cause the fish to use protein less efficiently for building muscle and tissue, leading to stunted growth and lower body weight.
• Lower feed efficiency: Studies on other fish have shown that growth performance and feed conversion ratios are directly proportional to the cysteine content in their diet.

Weakened immune response and disease resistance


One of cysteine's most important functions is acting as a precursor for glutathione (GSH), a powerful antioxidant that protects cells from damage.

• Increased oxidative stress: Without enough cysteine, the fish cannot produce enough glutathione. This leaves the koi susceptible to oxidative stress, which causes damage to tissues and impairs overall health.
• Compromised immunity: Oxidative stress can suppress the immune system, making the koi more vulnerable to infection from common pond bacteria and other pathogens. Research shows that adequate cysteine intake can significantly reduce fish mortality during disease outbreaks.

Negative impact on intestinal health

• Structural damage: Low dietary cysteine is linked to increased inflammation and structural damage in the intestinal tract.
• Impaired absorption: Damage to the intestinal villi can hinder the absorption of other nutrients, compounding the negative effects of the poor diet.

Does black soldier fly meal or insect meal contain amino acids that can replace the function of cysteine?

No, insect meals like black soldier fly (BSF) meal do not contain amino acids that can fully replace the function of cysteine. While they are a high-quality, sustainable source of protein and many amino acids, they are relatively deficient in the sulfur-containing amino acids, methionine and cysteine, when compared to traditional fishmeal.


For koi, this means:

• Insect meal can be a great component of a koi diet, but it cannot be the sole source of protein.
• High-quality koi feed using insect meal must be carefully formulated to ensure a balanced amino acid profile, often by adding synthetic methionine and cysteine or blending with other protein sources.

So, I went on to ask the following:
Does insect meal hold any health or growth advantages to a Koi Carp when compared to White Fish Meal or LT Hoki Meal?

For Koi carp, insect meals offer several advantages over traditional fishmeals like White Fish Meal or LT Hoki Meal, though proper formulation is essential.
Insects provide a sustainable food source with unique bioactive compounds that can boost immunity and aid digestion.

Fishmeal, however, provides a more complete profile of essential fatty acids, requiring supplementation when replaced with insect meal.

Feature	Insect Meal (e.g., Black Soldier Fly)	Fishmeal (e.g., White Fish Meal, LT Hoki Meal)
Protein Quality	High-quality, but can be lower in the sulfur-containing amino acids methionine and cysteine. Proper formulation requires balancing with other protein sources or supplements.	Excellent, with a balanced and complete amino acid profile, including high levels of methionine and cysteine.
Fatty Acid Profile	Often rich in saturated fatty acids (e.g., lauric acid). Can be deficient in long-chain omega-3 polyunsaturated fatty acids (EPA and DHA) unless the larvae's diet is enriched.	LT (Low-Temperature) Hoki meal is particularly rich in essential omega-3 fatty acids, which are critical for fish health. White fish meal also provides a good profile.
Digestibility	Highly digestible for Koi and can cause less waste.	Also highly digestible and a traditional benchmark for aquafeed.
Sustainability	Considered a highly sustainable, eco-friendly protein source. Black soldier fly larvae can be farmed on food waste, reducing the environmental footprint compared to capturing wild fish.	Relying on wild-caught forage fish for fishmeal production is a growing concern due to overfishing and ethical issues.
Cost	Cost-effectiveness can vary. While sometimes cheaper than fishmeal, the cost depends on production methods and scale.	The price of high-quality fishmeal is subject to increasing costs and scarcity.

I wonder what provides some of these ingredients in the 'wild' or huge acreage lakes.
60lb French carp aren't eating fish or therefore fish meal.

Originally Posted by Alburglar

I wonder what provides some of these ingredients in the 'wild' or huge acreage lakes.
60lb French carp aren't eating fish or therefore fish meal.

Carp anglers throwing in kilos and kilos of fish meal boilies and pellets

Originally Posted by g mac

Carp anglers throwing in kilos and kilos of fish meal boilies and pellets

They'll be some truth to that I should think.

I just can't believe that there will be anything better to feed them above what they have evolved to eat.

...and acts as a good warning to the other fish, not to be feeble.